npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@aesop-fables/containr

v0.6.1

Published

Inversion of Control container for Typescript

Downloads

178

Readme

@aesop-fables/containr

containr is a lightweight Inversion of Control framework for Typescript. It is based on concepts/apis from StructureMap and Microsoft's Dependency Injection tooling.

Installation

npm install @aesop-fables/containr
yarn add @aesop-fables/containr

Docs

Our docs our hosted on gitbook.

Usage

By and large, you really only do two kinds of things with containr:

  1. Configure the container by registering the what and how containr should build or find requested services based on a key.
  2. Resolve object instances of a service or dependency built out with all of its dependencies.

Registration

There are a variety of registration functions on the ServiceCollection class that you can use to control:

  1. How your value/class gets resolved
  2. When it gets resolved
Note:
v0.3* of `containr` introduced a new/simplified registration model. The team comes from a .NET background and sadly we bring some of that with us into Typescript generics sometimes. We're learning :).

1. factory(key: string, value: ValueFactoryDelegate, scope: Scopes)

Use this approach when you want to register a function to create your value/class. If you need service resolution, the function you register will receive an instance of IServiceContainer.

services.factory<string>(key, (container) => value, Scopes.Transient)

2. singleton(key: string, value: T)

Use this approach when you want to register a value directly.

services.singleton<string>(key, 'Hello, World!');

3. array(key: string, value: ValueFactoryDelegate<T> | T)

Use this approach when you want to add to an array of dependencies. This is useful when a class is depending an array of policies, etc. This approach is typically paired with the @injectArray(key: string) decorator.

services.array<string>(key, item1);

4. arrayAutoResolve(key: string, type: Newable<T>)

Use this approach when you want to add to an array of dependencies and also make use of containr's auto resolution pipeline. This approach is typically paired with the @injectArray(key: string) decorator.

services.arrayAutoResolve<IPolicy>(key, MyPolicy);

5. autoResolve(key: string, type: Newable<T>)

Use this approach when you want to register a class and make use of containr's auto resolution pipeline.

services.autoResolve<ISomething>(key, Something);

Scopes

Scopes control the lifetime and any caching of your dependencies. containr supports three scopes:

1. Transient

This is the default scope. Using this scope means that the container will cache your value. Most importantly, this scope is maintained when creating child containers if the value has already been resolved.

2. Singleton

This is the most straight-forward scope. Using this scope means that the container will cache your resolved value. This scope is always maintained when creating child containers.

3. Unique

Using this scope means that every attempt to resolve the dependency will result in a fresh instance (of the top-most dependency being requested).

Core Concepts

Configuring dependencies

In containr, values are registered against unique keys (strings). When you request for the container to get a dependency, you use a key to refer to it. The resolution logic works like:

  1. Delegate to the configured scope for managing lifecyle (i.e., transient, unique, singleton)
  2. When the dependency is being resolved and a factory was specified, invoke the factory (the scope may cache the value)
  3. Pass it along to containr's interceptor model.

The "Bootstrapping" Phase

The process of creating a container is known as the bootstrapping phase (or used as a verb to refer to the act of creating the container).

Auto Resolution

Due to limitations in Typescript's support for overloading, there are functions designed for registering dependencies to use auto-resolution (e.g., add, use).

Service Modules

Service modules are blocks of code that are used to modify a ServiceCollection. They're designed to be reused and shared across projects (exported from custom npm packages). While it can be argued that it overlaps with React's naming conventions for hooks, we've employed a use* naming convention for service modules (e.g., useMyApi).

Example

// CaseApi.ts
import { AxiosInstance } from 'axios';
import { AxiosKeys } from '@aesop-fables/containr-axios';
import { IErrorRelay, ErrorRelayKeys } from '@aesop-fables/containr-error-relay';
import { inject } from '@aesop-fables/containr';

export interface ViewCaseModel {
    id: string;
    title: string;
    // ....
}

export interface ICaseApi {
    getCaseById(id: string): Promise<ViewCaseModel | null>;
}

export class CaseApi implements ICaseApi {
    constructor(
        @inject(AxiosKeys.Axios) private readonly axios: AxiosInstance,
        @inject(ErrorRelayKeys.Relay) private readonly errorRelay: IErrorRelay,
    ) {}

    getCaseById(id: string): Promise<ViewCaseModel | null> {
        return this.errorRelay.execute<ViewCaseModel>('CaseApi', async () => {
            const { data } = await this.axios.get<ViewCaseModel>(`/cases/${id}`);
            return data;
        });
    }
}

// bootstrap.ts
import { createContainer, createServiceModule, Scopes } from '@aesop-fables/containr';
import { useAxios } from '@aesop-fables/containr-axios';
import { ICaseApi, CaseApi } from './CaseApi';
import CaseServiceKeys from './CaseServiceKeys';

const useCaseServices = createServiceModule('cases', (services) => {
    services.factory<ICaseApi>(CaseServiceKeys.Api, CaseApi, Scopes.Transient);
});

export default function() {
    return createContainer([
        useAxios,
        useCaseServices,
    ]);
}

// App.tsx
import React from 'react';
import bootstrap from './Bootstrap';
import { ServiceContainer } from '@aesop-fables/containr-react';

const container = bootstrap();
export const App: React.FC = () => {
    return (
        <ServiceContainer container={container}>
         // ...
        </ServiceContainer>
    );
};

// ViewCase.tsx
import React from 'react';
import { ICaseApi } from './CaseApi';
import { useService } from '@aesop-fables/containr-react';
import CaseServiceKeys from './CaseServiceKeys';

export ViewCase: React.FC = ({ route }) => {
    const { id } = route;
    const [isLoading, setIsLoading] = useState(true);
    const [caseModel, setCaseModel] = useState<ViewCaseModel | undefined>(undefined);
    const caseApi = useService<ICaseApi>(CaseServiceKeys.Api);
    // We're using our error-relay framework that connects to react
    // so errors are handled at a higher level
    
    useEffect(() => {
        (async () => {
            try {
                const model = await caseApi.getCaseById(id);
                if (model) {
                    setCaseModel(model);
                }
            } finally {
                setIsLoading(false);
            }
        })();
    }
    }, [id]);

    if (isLoading) {
        return <p>Loading...</p>;
    }

    if (!caseModel) {
        return <div />;
    }

    return <p>{caseModel.title}</p>;
};